Here's an interesting view on the initialization of a game. As it turns out, it is very similar to the way Sphere is designed.

The general theme here is based around the idea of the reuse of common GameLibraries. Basically the core executable contains the portable runtime and a DLL/SO loader. This core would load in the necessary modules for the game stored in DLLs and initialize them. Then a game specific script could be executed or perhaps a function could be called via an interface implementation obtained from a game DLL.